Experimental study of bluff-body stabilized highly turbulent premixed flames using pre-vaporized liquid fuels

本计画是一项高紊流预混火焰推进应用的实验研究。高湍流度是许多推进系统在小空间内产生高功率的共同特征。关于火焰与高湍流相互作用的科学知识仍然缺乏。这项研究将有助于更好地了解火焰湍流相互作用使用关键喷气燃料。该团队将进行这项研究，为公众提供高质量的实验数据。这项研究的技术潜在效益将是更好地设计燃烧系统的稳定运行和减少污染物。高效、低污染的燃烧系统将有利于环境和健康。该项目还通过培养高级博士生，为高技能劳动力的培养做出贡献。这项工作的目标是提高对高湍流（湍流强度高达40%）中钝体锚定预混火焰的火焰稳定性和稀薄喷出特性的基本认识。来流和湍流雷诺数高达8，100）。将采用带有盘形火焰稳定器的倒锥形火焰结构。国家的最先进的激光诊断（粒子图像测速仪和同步平面激光诱导荧光的羟基和甲醛）将被用来测量火焰结构/流场的相互作用，使高湍流燃烧制度的理解，还没有被充分探索之前。由此产生的实验数据也将用于验证高保真度数值模拟使用大涡模拟（LES）方法。预蒸发液体燃料的新的实验数据被用来记录和开发的预混合燃烧中的贫油吹脱现象的全面理解，因为它涉及到高度湍流，钝体回流区流动动力学，火焰流的相互作用。这些数据还将包括波纹火焰板和反应板在更高湍流状态下的火焰特性，而无需飞行火焰。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

This project is an experimental investigation of highly turbulent premixed flames for propulsion applications. High level of flow turbulence is a common feature of many propulsion systems to generate high power in a small space. Scientific knowledge of flame interactions with high turbulence is still lacking. This study will contribute to better understanding of flame-turbulence interactions using key jet fuels. The team will conduct this research to provide high quality experimental data for public use. Technical potential benefits of this research will be better design of combustion systems for stable operation and pollutant reduction. High-efficiency and low-pollution combustion systems will benefit both environment and health. This project also contributes to the development of highly-skilled workforce by training advanced doctoral degree students.The goal of this work is to improve the fundamental understanding of flame stabilization and lean blowoff characteristics in bluff-body-anchored premixed flames in highly turbulent flow (with turbulence intensities up to 40% in the approaching flow and turbulence Reynolds numbers up to 8,100). An inverted conical flame configuration with a disk-shaped flame stabilizer will be employed. State-of-the-art laser diagnostics (particle image velocimetry and simultaneous planar laser induced fluorescence of hydroxyl and formaldehyde) will be utilized to measure the flame structure/flowfield interactions, enabling the understanding of high-turbulence combustion regimes that have not been fully explored before. The resulting experimental data will also be utilized for validation of high fidelity numerical simulations using large eddy simulation (LES) methodology. New experimental data for pre-vaporized liquid fuels are used to document and develop a comprehensive understanding of lean blowoff phenomena in premixed combustion as it relates to highly turbulent flow, bluff-body recirculation zone flow dynamics, and flame-flow interactions. These data will also include the flame properties in the higher turbulence regimes of corrugated flamelets and reaction sheets without the need for piloted flames.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.